[AltStore] Adds redesigned BrowseViewController to browse and install apps

AltStore/Browse/BrowseCollectionViewCell.swift

@@ -0,0 +1,101 @@
+//
+//  BrowseCollectionViewCell.swift
+//  AltStore
+//
+//  Created by Riley Testut on 7/15/19.
+//  Copyright © 2019 Riley Testut. All rights reserved.
+//
+
+import UIKit
+
+import Roxas
+
+@objc class BrowseCollectionViewCell: UICollectionViewCell
+{
+    var imageNames: [String] = [] {
+        didSet {
+            self.dataSource.items = self.imageNames.map { $0 as NSString }
+        }
+    }
+    private lazy var dataSource = self.makeDataSource()
+    
+    private lazy var imageSizes = [NSString: CGSize]()
+    
+    @IBOutlet var nameLabel: UILabel!
+    @IBOutlet var developerLabel: UILabel!
+    @IBOutlet var appIconImageView: UIImageView!
+    @IBOutlet var actionButton: ProgressButton!
+    @IBOutlet var subtitleLabel: UILabel!
+    
+    @IBOutlet private var screenshotsContentView: UIView!
+    @IBOutlet private var screenshotsCollectionView: UICollectionView!
+    
+    override func awakeFromNib()
+    {
+        super.awakeFromNib()
+        
+        self.screenshotsCollectionView.delegate = self
+        self.screenshotsCollectionView.dataSource = self.dataSource
+        self.screenshotsCollectionView.prefetchDataSource = self.dataSource
+        
+        self.screenshotsContentView.layer.cornerRadius = 20
+        self.screenshotsContentView.layer.masksToBounds = true
+        
+        self.update()
+    }
+    
+    override func tintColorDidChange()
+    {
+        super.tintColorDidChange()
+        
+        self.update()
+    }
+}
+
+private extension BrowseCollectionViewCell
+{
+    func makeDataSource() -> RSTArrayCollectionViewPrefetchingDataSource<NSString, UIImage>
+    {
+        let dataSource = RSTArrayCollectionViewPrefetchingDataSource<NSString, UIImage>(items: [])
+        dataSource.cellConfigurationHandler = { (cell, screenshot, indexPath) in
+            let cell = cell as! ScreenshotCollectionViewCell
+            cell.imageView.isIndicatingActivity = true
+        }
+        dataSource.prefetchHandler = { (imageName, indexPath, completion) in
+            return BlockOperation {
+                let image = UIImage(named: imageName as String)
+                completion(image, nil)
+            }
+        }
+        dataSource.prefetchCompletionHandler = { (cell, image, indexPath, error) in
+            let cell = cell as! ScreenshotCollectionViewCell
+            cell.imageView.isIndicatingActivity = false
+            cell.imageView.image = image
+        }
+        
+        return dataSource
+    }
+    
+    private func update()
+    {
+        self.subtitleLabel.textColor = self.tintColor
+        self.screenshotsContentView.backgroundColor = self.tintColor.withAlphaComponent(0.1)
+    }
+}
+
+extension BrowseCollectionViewCell: UICollectionViewDelegateFlowLayout
+{
+    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize
+    {
+        let imageURL = self.dataSource.item(at: indexPath)
+        let dimensions = self.imageSizes[imageURL] ?? UIScreen.main.nativeBounds.size
+        
+        let aspectRatio = dimensions.width / dimensions.height
+        
+        let height = self.screenshotsCollectionView.bounds.height
+        let width = (self.screenshotsCollectionView.bounds.height * aspectRatio).rounded(.down)
+        
+        let size = CGSize(width: width, height: height)
+        return size
+    }
+}